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The European tent caterpillar, Malacosoma neustria Linnaeus (Lepidoptera: Lasiocampidae), is a worldwide known pest that causes significant losses by feeding on many woody and shrub-like plants during the larval period. In this study, a Beauveria bassiana strain isolated from M. neustria larvae and characterized according to its morphological and molecular properties. Its insecticidal activity was tested on M. neustria larvae. Sequence results of partial ITS (ITS1-5.8S-ITS2) gene region identified the isolate (named as Mn1) as a B. bassiana strain. Phylogenetic analysis showed that Mn1 strain displays close similarity to B. bassiana ARSEF 1848 and ARSEF 751 isolates. According to the concentration-responce tests performed using 1 × 10 3  - 1 × 10 9 conidia per mL concentrations, LC 50 value of the new strain was calculated as 1 × 10 5 conidia per mL within 7 days against the larvae of M. neustria in the laboratory conditions. B. bassiana Mn1 strain, characterized in this study, is recorded as the first entomopathogenic fungus isolated from M. neustria, and the results showed that new strain of B. bassiana has a serious potential to be utilized as a good biocontrol agent against M. neustria., (© 2023. Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i.)

Cydalima perspectalis (Walker 1859), the boxwood moth, is one of the important invasive pests spreading rapidly throughout Europe within a few years. The objective of the current research was to determine an alternative biological control agent for the control of C. perspectalis. Beauveria bassiana, an entomopathogenic fungus with high insecticidal activity, was isolated from the larvae of the pest that causes substantial economic losses on boxwood (Buxus sempervirens) in the eastern Black Sea region of Turkey, and its virulence was tested on it. Based on the morphological data and molecular characteristics, including the partial sequence of ITS (ITS1- 5.8S-ITS2 gene region) and EF1, the fungus was identified as an isolate of B. bassiana (CP1). In larval stage susceptibility tests, it was determined that larval mortality was higher in older stages. In concentration-response experiments using 1 × 104-8 conidia/ml, the LC50 value of the new isolate was calculated to be 1.7 × 104 conidia/ml within 10 days against C. perspectalis 6th instar larvae under laboratory conditions. This is a significant study to describe a novel B. bassiana CP1 isolate, and preliminary data suggests that the fungal isolate has considerable potential as an effective biopesticide for controlling C. perspectalis. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to develop an oil formulation from a local betabaculovirus. Hyphantria cunea Drury (Lepidoptera: Erebidae) granulovirus (HycuGV-Hc1) was isolated from the infected larvae to test its efficacy on the pest. The oil formulation was prepared by mixing the viral suspension with sunflower oil and some adjuvants and named HycuGV-TR61. Crude virus and the formulations were carried out on third instar H. cunea larvae using 1 × 104–8 OBs /ml concentrations and were exposed to temperatures (28, 35, and 42 °C) and UV-B light at different periods (0, 1, 3, 5 h). Results: The mortality rate, which was 50% at the lowest concentration (1 × 104 OB/ml), reached 99.86% at the highest concentration (1 × 108 OB/ml). LC50 values of fresh and old forms were calculated as 0.64 × 104 and 0.87 × 104 OBs/ml, respectively. Application of shelf life showed that there was non-significant change in the pathogenic activity of the formulation with time. In the experiments, it was observed that the activity decreased as the temperature and time of exposure increased. Significantly difference in larval mortality was observed when fresh and old formulations were exposed to 0, 1, 3 and 5 h to UV-B, (old: 96.7, 86, 80 and 60%; fresh: 97.1, 90, 85 and 62%, respectively). Conclusions: The results revealed superior aspects of HycuGV-TR61, which was developed as a local viral biopesticide, its resistance to abiotic factors and its potential to be used in pest control. [ABSTRACT FROM AUTHOR]

The gypsy moth (Lymantria dispar L., Lepidoptera: Lymantriidae) is one of the most serious pest of various forestal, food and industrial crops worldwide. We have characterized a new Lymantria dispar nucleopolyhedrovirus (LdMNPV-T4) variant, which was isolated from dead L. dispar larvae in Turkey. Scanning electron microscope observations showed that the polyhedral occlusion bodies (OBs) of the LdMNPV-T4 were irregularly shaped. Transmission electron microscopy revealed that OBs of LdMNPV-T4 were occupied with several virions in which multiple nucleocapsids packaged by viral envelope. Restriction analysis of the LdMNPV-T4 DNA purified from the viral inclusion bodies yielded BamHI, BglII, EcoRI and HindIII fragments. The mean size estimated for the complete LdMNPV-T4 genome was calculated to be 163.3 kb. Phylogenetic analysis of amplified polh, lef-8 and lef-9 sequences showed its relation to the other NPVs from Lymantria species. Mortality values of the LdMNPV-T4 at four different concentrations against third instar larvae of L. dispar ranged from 45% to 88%. These results suggest that LdMNPV-T4 isolated from Turkey is a promising microbial control agent to be utilized for the biological control of L. dispar. [ABSTRACT FROM AUTHOR]